Electrical connectors used for vehicles can be separated into two categories: those exposed to direct water contact and those not exposed to direct water contact. In the electrical connector corresponding to the former type, such as a connector used in an engine compartment, a rubber seal ring separate from a housing is interposed between, for example, a male housing and a female housing, thereby ensuring a high or fully waterproof performance. On the other hand, in electrical connectors corresponding to the latter type, such as a connector used for an electrical component within the vehicle, the waterproof performance is ensured by, for example, making some alterations on the structure of the housing instead of using the seal ring because only a light or partial waterproof performance is required.
Japanese Patent Application No. 2005-108499A, for example, discloses that water may spread through a small gap between the male housing and the female housing due to capillary action and may reach a terminal insertion hole which is located on the rear side of the electrical connector in the mating direction. JP 2005-108499A discloses that a recess is provided in the circumferential direction of the housing and water is accumulated in this recess, thereby preventing the water from flowing to the rear side of the electrical connector.
Although the waterproof performance is ensured until the recess of JP 2005-108499A is filled with water, when the amount of the water exceeds the capacity of the recess, the water overflows from the recess. Thus, when the structure disclosed in JP 2005-108499A is exposed to water which has exceeded a prescribed amount, the even light or partial waterproof performance of the connector is considerably impaired.